[Detection of human papillomavirus (HVP) 16/18 infections of the vaginal uterine cervix in females before and following conisation]. / Nachweis von humanen Papillom Virus (HPV) 16/18-Infektionen der Portio vaginalis cervicis uteri bei Frauen vor und nach Konisation.

280 women have been tested by FISH to detect an HPV 16/18-infection of the portio uteri. In a group of 133 women treated by conisation (all with a history of abnormal smear and colposcopy) 67 (50%) were positive for HPV 16/18 DNA before the operation. Follow up examinations of 20 cases with positive HPV 16/18 test before conisation, showed 6 and 12 months after operation only in 3 cases a persistence of HPV 16/18 infection. Only 5 (6.4%) of 78 women with a history of conisation and diagnosis CIN III some years ago were positive for HPV 16/18. In another group of 47 elderly women, treated by abrasio and with normal cervical histology, only 5 (10.6%) had a positive result in the HPV 16/18 FISH-test. 2 (10.6%) of 22 women with normal smear and colposcopy (control group) were positive for HPV 16/18.

Molecular cloning of integrated proviral DNA of bovine leukaemia virus from virus-producing foetal lamb kidney cells.

Over 90% of the total viral information together with the adjacent 5' cellular sequences were cloned in the lambdoid spi selection vector lambda-2558 by taking advantage of the unique EcoRI restriction site very close to the 3' long terminal repeat. Of the fifteen isolated recombinant phages with viral inserts, one has been propagated and its DNA isolated and subjected to preliminary restriction endonuclease analysis. The proviral insert has been found to be almost identical to the unintegrated proviral DNA reported by Kashmiri et al. (1984).

Inhibitor studies of phage T4 wild-type and mutant DNA polymerases. II. Differential inhibition by pyridoxal 5'-phosphate.

The sensitivities to pyridoxal 5'-phosphate of phage T4 wild-type and two ts mutant DNA polymerases, L98 (mutator) and CB 121 (antimutator), were studied. The wild-type and the mutator enzyme we inhibited to an equal extent, while the antimutator enzyme was six times more sensitive. The mode of inhibition was competitive with the deoxynucleoside triphosphate substrates. The CB121 DNA polymerase had a three times lower affinity to its substrates but a twofold affinity to pyridoxal 5'-phosphate. The L98 enzyme had lower affinities to both the substrates and the inhibitor.

Inhibitor studies of phage T4 wild-type and mutant DNA polymerases. V. A. summary of kinetic and inhibitor data.

The DNA polymerases of phage T4 wild-type, the mutator mutant L98 and the antimutator mutant CB121 were purified about 100-fold free of foreign enzyme activities interfering with the polymerase assay. The enzymes were characterized as to thermostability, exonuclease activity and kinetic data with DNA template primer, deoxythymidine 5' -triphosphate, and a mixture of all four deoxynucleoside 5' -triphosphates. The effects of eight inhibitors of DNA synthesis on the three enzymes were determined (Schroeder and Jantschak 1978 and 1980, Jantschak and Schroeder 1980) and are compared here. The most selective inhibitor, pyridoxal 5' -phosphate, interacts with the active site of the polymerases while the two least discriminating drugs, distamycin A and actinomycin D, do not directly interact with the polymerases at all. The study was intended to test whether specific enzyme inhibitors elicit a differential response in temperature-sensitive structural variants of this enzyme and whether, in principle, structural variants of virus enzymes or the respective ts- mutants in vivo are suitable as a screening system for selective antiviral agents.

Inhibitor studies of phage T4 wild-type and mutant DNA polymerases. III. Distamycin A, actinomycin D, adriamycin, daunomycin and ethidium.

Adriamycin, daunomycin and ethidium, intercalating drugs which bind to double- as well as single-stranded DNA, inhibit phage T4 antimutator mutant CB121 DNA polymerase more strongly than the T4 wild-type and the mutator L98 polymerase. In contrast, all three enzymes are inhibited equally by distamycin A and actinomycin C. The latter two inhibitors bind only to double-stranded DNA.

Inhibitor studies on phage T4 wild-type and mutant DNA polymerase. IV. The substrate analog 3'-fluorothymidine 5'-triphosphate.

The deoxythymidine-5'-triphosphate (dTTP) analog 3'-fluorothymidine 5'-triphosphate (3'-FdTTP) inhibits DNA synthesis by T4 wild-type, L98 (mutator) and CB121 (antimutator) DNA polymerase. CB121 DNA polymerase is less sensitive by a factor of two than the L98 and T4+ enzymes. Inhibition is not due to incorporation of the analog into DNA. 3'-FdTTP acts competitively to the substrate dTTP. The CB121 polymerase exhibits a higher Ki to Km ratio than the other two enzymes (5.3 vs. 3.3) and thus discriminates better between the substrate dTTP and its analog 3'-FdTTP. 3'-FdTTP inhibits the polymerase-associated 3'-5' exonuclease activities to the same extent as their polymerase activities. The CB121 3'-5' exonuclease activity is suppressed only half as much by 3'-FdTTP as by dTTP. The results are discussed in relation to the role of T4 DNA polymerase and its associated 3'-5' exonuclease in determining the accuracy of DNA replication.